#include<stdio.h>
int main()
{
    int a,b,c;
    int gcd(int ,int);
    printf("please enter two number .\n");
    c=gcd(a,b);
    printf("the gcd number is %d\n",c);
    
}
int gcd(int a,int b)
{
    int d;
    scanf("%d %d",&a,&b);
    d=a%b;
    while (d!=0)
    {
        a=b;
        b=d;
        d=a%b;
    }
   return b;
    
}